1. Field of the Invention
The present invention generally relates to the art of microphones and, more particularly, to a silicon based condenser microphone.
2. Description of Related Art
Silicon based condenser microphones, known as acoustic transducers, have been researched and developed for more than 20 years. Because of potential advantages in miniaturization, performance, reliability, environmental endurance, low cost, and mass production capability, silicon based microphones are widely recognized to be the next generation product to replace electret condenser microphones (ECM) that has been widely used in communication devices, multimedia players, and hearing aids.
A related silicon based condenser microphone comprises a backplate having a planar plate with a plurality of perforations therein, and a diaphragm parallel and opposed to the backplate for forming a capacitor. The diaphragm can be activated to move along a direction perpendicularly to the planar plate of the backplate.
However, a disadvantage of such microphone is that the air pressure of the air in the gap between the backplate and the diaphragm is unbalanced to that of the air outside. The present invention is provided to solve the problem.